Answer:
Experiments are most useful when investigating predictions derived from explicit theories, and it is theories, rather than experimental results, that are properly used to explain features of natural settings.
Answer:
to explore new possibilities
hope it helps
PLEASE HELP HURRY ILL MARK BRAINLEST
Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. ... Plant cells can be larger than animal cells.
Plz help already late in turning it in
Help meeeee pleaseee create a biography of an element
Answer:
Explanation:
A biography is a specialized form of history. It is an account of events based upon the example of one person's life. There are four basic types of biographies: historical fiction, academic, fictional academic, and the prophetic biography.
Heated gaseous atoms of elements emit light in unique colored patterns as electrons drop from
excited energy states to ground energy states. Heated hydrogen atoms have only four colored
lines, red, green, blue and violet. What prediction did Niels Bohr make about electrons based on
this information?
Answer:
b
Explanation:
Which of the following is a property of metals?
1. Olow melting point
2. O good electrical conductor
3. O good thermal insulator
4. O cannot bend without breaking
How many more valence electrons does this atom need to fulfill the Octet
Rule? (Urgent need help)
Answer: The octet rule is a bonding theory used to predict the molecular structure of covalently bonded molecules. According to the rule, atoms seek to have eight electrons in their outer—or valence—electron shells. Each atom will share, gain, or lose electrons to fill these outer electron shells with exactly eight electrons.
Explanation:
How many moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas?
Balanced equation: 2H2 + O2 → 2H2O (5 points)
a. 2 moles of water
b. 4 moles of water
c. 5 moles of water
d. 7 moles of water
Answer:
It is b
Explanation: I did it on the test and got it right
The moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas - b. 4 moles of water
The stoichiometric coefficients can be considered in a balanced equation as moles of reactants needed or moles of products formed in the reaction.
In the given case, the balanced chemical equation for this synthesis reaction looks like this2H2 + O2 → 2H2O
from the balanced equation, it is clear that the 2 moles of hydrogen gas and 1 mole of oxygen gas are required to produce 2 moles of water. so it means that the reaction produces twice as many moles of water as you have moles of oxygen gas that take part in the reaction and the same moles as hydrogen atoms present.Here it is given that there are only 2 moles of oxygen which means it is in deficiency however, it will produce 4 moles of water with four moles of hydrogen.Thus, the moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas - b. 4 moles of water
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Using the diagram to guide your answer, which of the following statements are true? Choose all that apply.
I The reactants (initial) contain 6 atoms of hydrogen and 2 atoms of nitrogen
The products (final) contain two atoms of nitrogen and six atoms of hydrogen
I The number of atoms is the same in the initial and final boxes
2 molecules of nitrogen react with 3 molecules of hydrogen to produce 2 molecules of ammonia
The number of molecules is the same in the initial and final boxes
Answer: The reactants (initial) contain 6 atoms of hydrogen and 2 atoms of nitrogen
The products (final) contain two atoms of nitrogen and six atoms of hydrogen
The number of atoms is the same in the initial and final boxes
Explanation:
Atom is the smallest unit of an element which may or may not exist independently.
Molecule is the smallest unit of a pure substance that consists of two or more atoms held together by a chemical bond .
Molecule of a Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass. Example: [tex]NH_3[/tex]
Molecule of an element is a pure substance formed by combination of same types of atoms bonded by a chemical bond. Example: [tex]H_2[/tex] and [tex]N_2[/tex]
Here one molecule of nitrogen ([tex]N_2[/tex]) combines with 3 molecules of hydrogen ([tex]H_2[/tex]) to give 2 molecules of ammonia. ([tex]NH_3[/tex]).
I will give you Brainly if you awser correct if your gonna awser for points pl put I don’t know
Answer:
C
Explanation:
What is different about the transition metals and
their charges from other groups on the periodic
table?
A: Their charge is positive but not always the same each
time
B: Their charge is negative but not always the same each
time
C: they are usually neutral
Answer:
i think a im not 100 %sure
Explanation:
Most transition metals differ from the metals of Groups 1, 2, and 13 in that they are capable of forming more than one cation with different ionic charges. It can sometimes lose two electrons to form the Fe2+ ion, while at other times it loses three electrons to form the Fe3+ i hope it helped
Can farmers simply plant more acres of crops to feed a growing population?
Answer:
I believe they can if it's a small town/village
Explanation:
WILL GIVE BRAINLIEST (major help!!! need now!!!) David observed properties of four different compounds, only one of which is an ionic compound. His observations are shown in the chart.
A 2-column table with 4 rows. The first column labeled compound has entries W, X, Y, Z. The second column labeled observations has entries is a hard solid, melts at 44 degrees C, has a molecular structure; is a brittle solid, does not conduct electricity in water, has a crystal structure; is a hard solid, conducts electricity, has a molecular structure; is a brittle solid, melts at 801 degrees C, has a crystal structure.
Which is most likely the ionic compound?
W
X
Y
Z
Answer:I think it’s y sorry if I’m wrong
Explanation:
Answer:
i think it might be y
Explanation:
on 100 corex
c с
A flask contains helium and nitrogen
gases. The partial pressures of each are
77 mm Hg and 87 mm Hg, respectively.
Help Resources
What is the total pressure in the flask mm Hg
Answer:
P(total) = 164 mmHg
Explanation:
Given data:
Partial pressure of helium = 77 mmHg
Partial pressure of nitrogen = 87 mmHg
Total pressure of flask = ?
Solution:
According to Dalton law of partial pressure,
The total pressure inside container is equal to the sum of partial pressures of individual gases present in container.
Mathematical expression:
P(total) = P₁ + P₂ + P₃+ ............+Pₙ
Now we will solve this problem by using this law.
P(total) = P(He) + P(N₂)
P(total) = 77 mmHg + 87 mmHg
P(total) = 164 mmHg
An oxide of arsenic contains 3.26 g of arsenic and 1.04 g of oxygen. What is the empirical formula for this oxide?
The empirical formula for this oxide : As₂O₃
Further explanation:
Given
mass of Arsenic=3.26 g
mass of Oxygen = 1.04 g
Required
The empirical formula
Analysis
find mole of elementsdetermine the ratio of each elementSolution
mol of Arsenic(MW=74,9216 u) :
[tex]\tt mol=\dfrac{3.26}{74,9216}=0.0435[/tex]
mol of Oxygen(MW=15.999 u) :
[tex]\tt mol=\dfrac{1.04}{15.999}=0.065[/tex].
The ratio for each element (divide by smaller mol⇒Arsenic)
Arsenic : Oxygen :
[tex]\tt \dfrac{0.0435}{0.0435}\div \dfrac{0.065}{0.0435}=1\div 1.5\rightarrow 2\div 3[/tex]
The empirical formula : As₂O₃
You witnessed a student throw away a broken beaker in the regular trash can. Which of the following is the most important reason to alert your instructor?
Answer:
D
Explanation:
how does skin protect the body from pathogens?
A it produces whit blood cells that reconize and eat pathogens.
b it transsfers pathogens to lymph and blood plasma
c it traps pathogens in oil and seat produced by glands.
d. it has hairs that sweep pathogens away from the body
Answer:
C: It traps pathogens in oil and sweat
Explanation:
The skin has oil and sweat which kills pathogens as they are like a waterbarrier.
The skin protects the body from pathogens by trapping pathogens in oil and sweat produced by glands. Thus, the correct option for this question is C.
What are Pathogens?Pathogens may be defined as those living organisms which are capable of inducing diseases in other living organisms including humans. Some examples of pathogens include bacteria, fungi, protozoa, etc.
Skin is considered the first line of defense against pathogens in humans. This is because skin significantly consists of sebaceous and sweat glands that consistently secrete oils and sweat that trap the pathogens and eliminate them from entering the body.
Therefore, the skin protects the body from pathogens by trapping pathogens in oil and sweat produced by glands. Thus, the correct option for this question is C.
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evanrosario11 avatar
evanrosario11
7 minutes ago
Physics
High School
100 Points + Brainlest PLZ HElP
What ion would each of the following elements form?
For example, a sodium atom (Na) will form a sodium ion (Na+1). You will need to list the charge of the ion. You will need to list the charge of the ion for the seven questions below.
1. Beryllium (Be)
2. Sulfur (S)
3. Potassium (K)
4. Aluminum (Al)
5. Bromine (Br)
6. Oxygen (O)
7. Magnesium (Mg)
Answer:
Forming positive ions
Explanation:
A sodium atom has one electron in its outer shell. ... It will still have 11 positive protons but only 10 negative electrons. So, the overall charge is +1. A positive sign is added to the symbol for sodium, Na +.
Hope it helps
xoxo
Explanation:
Forming Positive Ions
Hope It Helped U
in which group on the periodic table does the atom pictures belong?
a) 4
b) 6
c) 16
d) 14
Answer: Group 14
Explanation:
It's a carbon atom with 4 valance electrons.
Rubidium is a soft, silvery-white metal that has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, what is the average atomic mass of Rubidium?
The average atomic mass of Rubidium : 85.226 u
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
Mass atom X = mass isotope 1 . % + mass isotope 2.%
The abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, so the average atomic mass of Rubidium :
[tex]\tt the~average~atomic~mass=0.8\times 85+0.198\times 87\\\\the~average~atomic~mass=\boxed{\bold{85.226~u}}[/tex]
What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44
M solution?
30 M
40 M
50 M
5M
Given :
Volume of stock solution, [tex]V_s = 20\ mL[/tex].
Volume of diluted solution, [tex]V_d = 400 \ mL[/tex].
Molarity of diluted solution, [tex]M_d = 1.44\ M[/tex].
To Find :
The concentration of the stock solution.
Solution :
We know, dilution factor is given by :
[tex]D.F=\dfrac{V_ {diluted}}{V_{stock}}[/tex] ....1)
and [tex]D.F= \dfrac{M_{stock}}{M_{diluted}}[/tex] ....2)
Putting volume in above equation, we get :
D.F = 400/20
D.F = 20
Putting value of D.F in equation 2) we get :
[tex]\dfrac{M_{stock}}{M_{diluted}} = 20\\\\M_{stock} = 20\times 1.44\\\\M_{stock} =28.8\ M[/tex]
The concentration of stock solution is nearest to 30 M.
Therefore, the correct option is 1) 30 M.
a ball with a mass of 20 kg is accelerating at 4 m/s/s while being thrown . about how much force was used to throw the ball
Answer:
80 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 20 × 4
We have the final answer as
80 NHope this helps you
Answer:
80 n
Hope I helped
The process of making proteins is called protein
Answer:
protein sysnthesis
Explanation:
Which phrase accurately describes the location of Africa? O mostly in the eastern hemisphere mostly south of the Tropic of Capricorn O borders the Pacific Ocean O lies north of Europe
Answer:
mostly in the eastern hemisphere mostly south of the Tropic of Capricorn
Explanation:
The statement which best describes the location of Africa is that it is found
mostly in the eastern hemisphere.
Africa is a continent which comprises of countries such as Nigeria, Ghana,
Kenya etc. It is bounded on the north by the tropic of cancer and towards
the south of the tropic of capricorn.
Africa also lies in the eastern hemisphere and is found to the south of the
European continent.
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if you had 15 moles of Oxygen (O2), how many moles of water (H2O) would you be able to make?
Answer:
30 moles of water will produced.
Explanation:
Given data:
Number of moles of O₂ react = 15 mol
Number of moles of water formed = ?
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Now we will compare the moles of water with oxygen.
O₂ : H₂O
1 : 2
15 : 2×15 = 30 mol
30 moles of water will produced.
Explain why the following structure is incorrect
Answer:
there is too many electrons around the shell
Explanation:
You have a shiny metal disc that weighs 1.31 kg that you want to find out what its made of. When you put the disc into a graduated cylinder with 5L in it, you see that the water level rose by about 125 mL. You have a list of densities for various shiny metals: silver= 10.5 g/ mL, nickel= 8.9 g/mL, titanium = 4.5 g/mL, and rhodium = 10.7 g/ mL. What is the disc made of?
Answer:
The disc is made of silver.
Explanation:
To solve this question we need to calculate the metal's density. To do so we need its mass (already given by the problem, 1.31 kg) and its volume.
Following Archimedes' principle, the volume of water displaced by the disk is equal to the disk's volume. This means the metal's volume is 125 mL.
Now we convert 1.31 kg into g, to better compare with the given options:
1.31 kg * 1000 = 1310 gFinally we calculate the metal's density:
Density = Mass / VolumeDensity = 1310 g / 125 mL = 10.48 g/mLLooking at the densities given by the problem, the closest one is silver.
what statements are true about Volume
Answer:
B,C,D
Explanation:
Hope this helps.
help me id.k this. this is so hard...
Answer:
it's 2:1
ask me if you want explaination also. it is just an mcq that's why i am not giving
thank you
Please help with this I do not under stand
Answer:
See below:
Explanation:
The grasshopper doesn't require an exchange of gasses (air) using a circulatory system because the gasses directly reach its cell's from the "air sacs" which spread out into tiny tubes close to each cell.
You’ve been waiting for the bus and your hands become cold. When you get onto the bus and sit down, you put your hands under your legs to warm up. After a while your hands feel warmer but your legs feel colder. Explain this with regards to what you know about thermal energy transfer.
Explanation:
The First Law of Thermodynamics states that energy cannot be created or destroyed in an isolated system. In other words, energy can be converted from one form into another, but it cannot be created nor destroyed.
Conduction is the transfer of energy from one molecule to another by direct contact. This transfer occurs when molecules hit against each other, which can take place in solids, liquids, and gases.
When you put your cold hands under your legs to warm your hands up, the heat energy from your legs is being transferred to your hands through conduction. However, since energy cannot be created, there is no extra heat energy that can instantaneously replace the heat created by your legs.
Every metabolic process involves energy transfer. Since as the total energy is conserved and thus no loss or gain of energy will be there in a system and to maintain this equilibrium energy transfer from lower energy spot to higher energy spot.
What is thermal energy?Thermal energy is the energy in the form of heat and which can transfer from one part to the other as any other energy form.
As energy is conserved in a system there will be no net gain or loss of energy overall. Thus energy lost from one part travels to the other parts. Any energy forms transfer from a low intense area to high intense area.
When our hand cools down we may warm them up by rubbing on legs. Where heat energy is transferred from our legs to hands to warm it up. Thus here temperature is given to a colder part from a hot part.
This is an example of heat transfer hence, our legs cools down because some of its temperature is lost to hands still the overall temperature of the body remains balanced.
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